Chair



Jan. 20, 1931. w. HJLEFFINGWELL 1,789,331

CHAIR Filed Nov. 10. 1927 2 Sheets-Sheet l gvwmwoz 6 y @513 Gb tomwiyJan. 20, 1931. w. H. LEFFINGWELL C HA IR Filed Nov 10. 1927 2Sheets-Sheet 2 awueutoz @Mowww Patented Jan. 20, 1931 I r r unrrsn rsATENT new; i

WILLIAM-n. L'nrrmewnnt, or WEST-FIELD, New JERSEY oHAIR Applicationfiled November 10,1927. Serial No. 232,215.

This invention relates to. an improved detweenthe buttocks and'thighsthus avoiding signin the art of chair buildin and parany pressure on theunder side of the knees. ticularly those types of chairsadapted for thein the ordinary chair the seat is madefiof use in schools, oliices andfactories, etc, such a depth thatthe user, in endeavoring towhereinsedentary occupations are required. sit with his back against theback of the 'It has long been known that incorrect seat chair, creates apressure on the nerves and ingpositions cause numerous internal ailbloodvesselsinthe popliteal region. Asthe ments, such as indigestion,constipation, imveins and nerves in this region (under the propercirculation of the blood and certain knee) are very near the surface anypressure 10 nerve diseases caused by undue pressure on oi whateverdegree makes for a retarded ac- 6O '1 hours.

the nerves. Also improper breathing action tion, sometimes causingsciatica, neuritis and may be caused by acramped position of the aslowing up of the circulation. lungs,together with the usual fatigue oneeX- Another object of my invention is to properiences after remainingseated tor a few vide a chair with a seat of just'sufiicient depth 9 toenable the user to sit comfortably without Here'tofore anumber ofattempts have been producing a binding efiect under-the knee. made tocorrect this trouble by shaping chairs One of the causes of the bodyfatigue exto conform to the anatomy of the body; none perien'ced bythose in sedentary occupations of which was entirely successful, due tothe is that either no back rest is provided at all or fact that no twopeople or groups of people the one providedis practically useless, doingare exactly alike, and consequently a. chair more harm than good. Incases where there' made to fit one or a group of persons will not is aback rest it is oftentimes too high or too be anatomically correct foranother person of low and no means is provided for adjusta differentbuild. ing it to suit the back of'the user. Attempts I 95 One of thechief causes of internal body have been made, usually by inexperienced"ailments is the fact that the ordinary straight workers, to provide backrest of a shape back chair is uncomfortable to siton and, in tofit't'li'e body without first making a scienorder toease his positionsomewhat, the user 'tific studyto ascertain the sliape,position andunwittingly slides forward, thus casting the requirements of the humanbody. weight of his body on the' lower partof the These attempts havebeen successful only spine instead of onthe lower part otthe pelin asmall degree for the reasons heretofore vis. In this position, thespine, instead of stated. Another object of my invention is being erectand straight, assumes a. curved to construct a'chair withscientificallydeposition cramping the organs of the abdosigned andpositioned back support andone v men, and the lungs, and eventuallyresulting thatmay be readily and conveniently adjust- 35 in the bodyailments hereinbefore mentioned. ed by the user while seated.

Also thesc in'correct sitting postures inter- A deeply curved shoulderrest also has the ferc with proper circulation'of the blood, anddisadvantage of crouuling the shoulders forthereby induce a fatigue,which in no reward, causing a collapsed condition oi. the spect dueto-the work done, whether its charchest aud thereifore another object ofmy inacter be mental or manual. vcution is to provide a shoulder supportfor A bje t. f m i ti n is to providea a ch air which will tendto'iiaitten the scapuchair for the offic worker, typisg-t l ph lac on.the back and provide the necessary operator, etc., that will preventthebody room for the proper functioning of the from slipping forward andhold it in erect 1;},6- I I upright position, thereby allowing theorgans From the foregoing it will .be apparent that ofthe body tofunctionin their normal mannearly all, it not entirely all, of the nudener. Another object of my invention is 'to sirable features of theordinary chair have so shape the seat ofthe chair that the weight, beeneliminated in my design for a chair disof the trunk is more evenlydistributed beclosed herein. 'As a further object of my involition, Ipropose to make a chair in which the user may relax completely withoutfalling into a slumped or other improper detrimental position.

To accomplish these and other objects of my invention, 1 provide a chairwith a shorter seat than is customarily provided and one that is shapedto comfortably fit the body in the seated position. The front edge ofthe seat is recessed the proper amount required to give freedom to themovement of the legs and without interfering with the circulatory ornervous s terms. The rear portion of the seat is sufficiently recessedto give the correct posture position and also to maintain the body in anm'inalhealthy erect position. To support the back and shoulders, Iprovide cross pieces mounted on upright supports located at the rearpart of the seat; each upright support being so designed as to offer noobstruction to the arms or body. The shoulder support is curved slightlyto fit the bony, without crowding or cramping the lungs; while the backsupport for the houbar region is curved slightly in two directions tomore accurately conform to the contour of the occupants back. One of theimportant features of this invention is the mountin and functions ofthis back support. '10 overcome the disadvantages of prior deviceshaving a fixed support for the lumbarregion I propose to mountthe support in a vertically adjustable manner and allow it to swing slightlyabout a horizontal axis. Thus, it will be seen that a chairincorporating this adjustable feature may be readily adapted to fit theback of any. person using it.

Other objects and advantages will be in part indicated in the follmvingdescriptions and in part rendered apparent therefrom in connection withthe annexed drawings.

To enable others skilled in the art so fully to apprehend the underlyingfeatures hereof that they may embody the same in the various wayscontemplated by this invention, drawings depicting a preferred typicalconstruction have been annexed as a part of this disclosure and, in suchdrawings, like characters of reference denote corresponding partsthroughout all the views, of which Figure 1 is-a front elevational viewof a chair embodyingmy invention. Fig. 2 is a side elevation thereofshowing, in dotted lines. a central vertical. section through theshoulder and back support to more clearly rate their shape and relativepositions. G3 is a plan view of the chair seat and back supportingmembers showing their relative positions. one above the other and theircurves. Figs. at, 5. 6.1", 8, and 9 are sectional views along es blit,55, 66, 7*]: 8S, and 99. r ectively of Fig. 3 showing more clearly thedegree of recessing given to the seat member. Fig. 10 is a fragmentaryvertical sectional view through the back supporting members showing theshapes of their respective forward faces and the vertically adjustableswiveled mounting for the back support. Fig. 11 is a fragmentary frontview of the chair back with parts thereof broken away to show moreclearly the mounting of the lumbar rest. Fig. 12 is a. section throughline 12-12 of Fig. 11, showing the notched plate for retaining thelumbar rest in position.

7 Referring more particularly to Figs. 1 and 2 this invention isdisclosed as incorporated in a chair having a well known type ofstandard and, as this invention relates only to that part of a chairfrom the seat up, it is to be understood that any type or style ofstandard maybe used; the type shown in the drawings is for convenienceof illustration only. The posture chair proper combines a deeplyrecessed seatmember 1, with two upright supports 2, which arescientifically shaped to more closely conform to the body and designedso as to be free of any obstructions to the arms or lmttocks.

Referring to Figs. 2 to 9 inclusive, it will be not-ed that the designof the seat member 1 presents a radical departure from the usual type ofchair seat. The depth of the seat is preferably made considerablyshorter than it is usually constructed to enable the occupant to sitcomfortably thereon without sliding forward to gain thenecessary roomfor the bending of the leg at the knee joint. The front edge of the seatI propose to shape, as shown in Fig. 9, with a large downward curveremoving that part of the seat which ordinarily creates a pressure onthe underside of the knee of the occupant.

The rear portion of the'scat member 1 is formed with a deep bowl-shapedrecess a as indicated in the sectional Fi s. 7, S and 9; the forwardportion of which cooperates with the forwardly disposed longitudinalhump 71. to form the relatively steep incline'c. The incline 6 extendsforwardly on either side of'the hump 72 and forms two shallow channels 8properly contoured to fit the thighs of the user. It, therefore, becomesapparent that by reason of the contour of the surfaces 7', e, h and s onthe seat member 1, a proper, accurate, form-fitting support is formedfor the gluteofemora-l muscles of the user. I

The upright supports are preferably two in number for the reason to'behereinafter stated, but it will be understood that any number ofsupports may be employed without departing from the spirit of thisinvention. As shown in Fig. 2, the upright supporting members are shownin a fixed position with relation to the floor member 1 of the chair andextend upwardly with a gradual inclination toward the rear. As iscustomary in the design of many office chairs,

the back supportis either pivoted, at a point near the seat member orthe seat itself mounted on a pivot so as to permit the user to rockbackward whenever he wishes. This feature of the usual office chair hasthe disadvantage of shifting the weight of the trunk of the body fromthe lower part of the pelvis to the spinal column and thus an incorrecthabit of sitting posture results. The above notet faults are correctedin the invention disclosed herein; the proper angle of inclination ofthe back support with respect to the chair seat remains always the Thesupports 2 are separated as shown in Fig. 1, to allow ample room for thebuttocks gluteal muscles, and thus it will be seen any person, w tetherof large or small build, may comfortably sit all the way back in thistype of chair and by so doing get the full benefit of the contour of theseat member and also of the back and shoulder rests.

At the upper end of the upright support ing' member 2, it has been founddesirable to securely fix thereto a shoulder support 3 having the propercurves and shape, as indicated at a and b. The curve a is so designed asto afford a restful support for the shoulders of the user while workingwithout cramping or interfering with the normal movements of the scapulmor arms.

Betweenthe shoulder support 3 and seat.

member 1, and within the plane of the up rightsupports 3, I mount a backsupporting member 4 to support that part of the users back known as thelumbar region. A critical point in the design of posture chairs is theproviding of an anatomically accurate support for this part of the backas it is in this region the worker tires first. As hereinbefore stated,supports have been made for this part of the back but have provedunsuccessful in that they were not adjustable to suit the back of theuser and did not cooperate with the form of seat to bring about thedesired result.

The support t in this improved posture chair is mounted as at 5 so as topermit vertical adjustment thereof and also pivoted as at- 6 so as tomove with the body and afford a resting support in all positions. Asshown in the drawings, the adjustable feature consists of the notchedplates 7 attached to the upright supports and pivots 8 fixed to themember A. A recess 7* is formed in each of the upright members 2 toprovide clearance for the pivots 8 when moved into any of the notches 7"formed in the plates 7. Obviously other suitable means for mounting thecross member 4.- so as to have a pivotal and vertical adjustment may beemployed and therefore I do not limit myself to the precise constructionshown in the drawings. An 1mportant feature is that the seat is formedof the back "tothe pos tion of the occupant brought about to overcomeany'tendency of the body to-slip forward, while the support a bracesthat part especially needing support due area. The curve a in theverticalplane, more accurately fits the contour of the spinal col- 'umnand due to its pivotal movement the member 4 readily adaptsltself to fitthe 0011-,

tour of the l acks of a larger number of-nsers The dotted line'POSlijlOllS'Sl'lOWl'l'lll Fig. 10

serve to illustrate the pivotal mmen'ieint of the back 'rest member l,while the vertical adjustment thereof may be attained by moving the resta forwardly out of one of the notches 7 of the plates 7 and raising orlowering as desired, all of which may be quickly and easily done by theperson wl'iile seated.

It therefore becomes apparent that all the nnportant features of thistype of chair cooperate together to bring about a eorrectposture sittingposition and that the omission of one' or more creates a deleteriouseffect onthe 'user.

back ant shoulders, and conversely, produces an in urious result, or thelack of ample room for the buttocks tends to cause a forward movement ofthe body and consequently the.

user sits in anincorrect and harmful position.

Vithout further analysis, the foregoing will so fully reveal the gistofthis in vention that others can, by applying current knowledge, readilyadapt it for various i utilizations by retaining one or more of thefeatures that, from the standpoint of the prior art, fairlyconstituteessential characteristics of either the generic or specificaspects of this invention and, therefor, such adaptations should be, andare intended to be, comprehended within the meaning and range ofequivalency of. the following claims 2- Having thus revealed. thisinvention, I claim as new and desire to secure the followingcombinations and elements, or equivalents thereof, by Letters Patent ofthe United States i l. A posture chair comprising a saddle For example,a recessed seat. member without the proper support forthe' the saidlumbar rest being of a shape and size to form a support for the lowerpart of the back of said occupant, whereby the lumbar rest will betilted to different positions by contact of the occupants back, the twocontacting surfaces of the lumbar rest and shoulder rest with the backof the occupant being capable of being projected into different relativeinclinations, one to the other, to enable the occupants back to besupported in erect position at both the shoulders and at a pointadjacent the base of the spine, while permitting the occupant to flexthe portion adjacent the base of the spine into different postures inorder to overcome the normal tendency to shift the buttocks, therebymaintaining the buttocks in proper position on the seat.

2.111 a chair of the character described the combination of a seat withuprights projecting therefrom and spaced a substantial distance apart,said seat having a depression extending between the uprights, a humpformed on the forward part of said seat adjacent said depression, saidhump being adapted to maintain the normal position of the buttockswithin said depression, a fixed shoulder rest on said uprights, a lumbarrest pivot-ally mounted at a point adjacent the base of the spine and ofa size and shape to afford a satisfactory support to the lower portionof the back of the occupant capable of being tilted by the occupantsback while the shoulders are pressed against the shoulder rest to changethe inclination of the surfaces of the lumbar rest and the shoulder restin their relation, one to the other, whereby the occupants back will beproperly supported both at the shoulders and near the base of the spine,said lumbar rest being automatically oscillated by any movement of thelower portion of the body, thereby permitting the occupant to flex thesaid portion of the bod into different positions counteracting anytendency to shift the buttocks out of correct position within saiddepression.

In witness whereof, I have hereunto subscribed my name.

lVILLIAM H. LEFFINGWELL-

